Use of peroxisome proliferator activated receptor (PPAR)-γ ligands as a treatment for pituitary tumors and associated conditions, such as Cushing's syndrome

Abstract

Disclosed is a method for treating a pituitary tumor in a mammal, employing the administration of a peroxisome proliferator activated receptor gamma ligand (also known as “peroxisome proliferating-activator receptor gamma” or “PPAR-γ”). In some embodiments, the peroxisome proliferator activated receptor gamma ligand is a thiazolidinedione compound. Also disclosed are methods for preventing the formation of a pituitary tumor in a mammal and for preventing the recurrence of a pituitary tumor in a mammal. Further disclosed is a method for treating a mammal exhibiting one or more symptoms of Cushing's syndrome.

We claim:  
     
       1. A method for treating a non-cancerous pituitary tumor in a mammal, comprising: 
       administering to a mammal having a non-cancerous pituitary tumor an effective amount of at least one peroxisome proliferator activated receptor gamma ligand.  
     
     
       2. The method of  claim 1 , wherein the at least one peroxisome proliferator activated receptor gamma ligand is a thiazolidinedione compound. 
     
     
       3. The method of  claim 1 , wherein the thiazolidinedione compound is selected from the group consisting of rosiglitazone, pioglitazone, and troglitazone. 
     
     
       4. The method of  claim 1 , wherein the pituitary tumor is an ACTH-secreting, LH-secreting, GH-secreting, or PRL-secreting pituitary tumor. 
     
     
       5. The method of  claim 1 , wherein the pituitary tumor is a non-functioning pituitary tumor. 
     
     
       6. A method for preventing the formation of a non-cancerous pituitary tumor in a mammal, comprising: 
       administering to a mammal at higher than normal risk for developing a non-cancerous pituitary tumor an effective amount of at least one peroxisome proliferator activated receptor gamma ligand.  
     
     
       7. A method for preventing the recurrence of a non-cancerous pituitary tumor in a mammal, comprising: 
       administering to a mammal, said mammal previously having had a detectable, non-cancerous pituitary tumor that was eliminated, an effective amount of at least one peroxisome proliferator activated receptor gamma ligand, whereby recurrence of the non-cancerous pituitary tumor is prevented.  
     
     
       8. A method for treating a mammal exhibiting one or more symptoms of Cushing's syndrome resulting from hypersecretion of adrenocorticotrophic hormone (ACTH), comprising: 
       administering to the mammal an effective amount of at least one peroxisome proliferator activated receptor gamma ligand.  
     
     
       9. The method of  claim 8 , wherein the symptom of Cushing's syndrome is steroid hypersecretion. 
     
     
       10. The method of  claim 8 , wherein the symptom of Cushing's syndrome is elevated urinary cortisol excretion. 
     
     
       11. A method for treating a non-functioning, non-cancerous pituitary tumor in a mammal, comprising: 
       administering to a mammal having a non-functioning, non-cancerous pituitary tumor an effective amount of at least one peroxisome proliferator activated receptor gamma ligand.  
     
     
       12. The method of  claim 11 , wherein the at least one peroxisome proliferator activated receptor gamma ligand is a thiazolidinedione compound. 
     
     
       13. The method of  claim 11 , wherein the thiazolidinedione compound is selected from the group consisting of rosiglitazone, pioglitazone, and troglitazone. 
     
     
       14. A method for treating a non-functioning, non-cancerous pituitary tumor in a mammal, comprising administering to a mammal having a non-functioning, non-cancerous pituitary tumor an effective amount of a thiazolidinedione compound. 
     
     
       15. A method for treating a non-functioning, non-cancerous pituitary tumor in a mammal, comprising: 
       administering to a mammal having a non-functioning, non-cancerous pituitary tumor an effective amount of a thiazolidinedione compound selected from the group consisting of rosiglitazone, pioglitazone, and troglitazone.